When I was at the APA Pacific Division conference at the end of March, I attended an interesting talk by Matthew Slater opposing mereological moderation – the doctrine that for some things, there is an object made up of them as parts, and for some things, there is no object such that every part has a part that is part of one of those things. However, he suggested that he might be neutral between nihilism (the thought that no collections of things are the parts of some further thing) and universalism (the thought that any collection of things is the parts of some further thing).
It seems to me that if these really are the choices, then Hartry Field’s nominalist reconstruction of physics pushes us most definitely towards the latter. He has to quantify over non-atomic entities in order to do physics, so at least some entities must have non-trivial parts. But this just means that nihilism is not an option. To embrace this nihilism would mean a definite rejection of Field’s program, and thus an embrace of (perhaps more troubling?) abstract objects, rather than composite physical objects.
Not knowing the literature, I don’t know if this argument has already been made (or if the naturalistic prejudice it has is considered legitimate there), but it’s what I was thinking when I was at that talk.